US20170077573A1 - Transverse magnetic (tm) mode dielectric filter - Google Patents

Abstract

A transverse magnetic (TM) mode dielectric filter includes an enclosure, a dielectric resonator, a main cover, and an elastic component, where the dielectric resonator is disposed in a resonant cavity of the enclosure; the main cover is secured between the elastic component and an open end of the enclosure; the elastic component includes multiple elastic flaps; the multiple elastic flaps are evenly distributed around an axial direction of the dielectric resonator; one end of each of the elastic flaps is fixedly connected to the main cover, and free ends of the elastic flaps elastically act on a central part of an outer surface of the main cover, to provide an elastic force towards the dielectric resonator. The evenly distributed multiple elastic flaps produce a pressure towards the dielectric resonator. A uniform and stable pressure is produced around the dielectric resonator, to ensure a uniform current density inside the resonant cavity.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of International Application No. PCT/CN2014/076963, filed on May 7, 2014, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
• The present invention relates to a filter, and in particular, to a transverse magnetic (TM) mode dielectric filter.
BACKGROUND
• A filter, as a frequency selection apparatus, is widely applied to the communications field, and in particular, to the field of radio frequency communications. In a base station, a filter is used to select a communications signal, filter out a clutter signal or an interference signal beyond a communications signal frequency, and reserve a wanted signal within a passband. With a gradually growing mass production requirement for miniaturized, high-performance, and high-power filters in the communications field, a current metal coaxial cavity filter gradually becomes incapable of satisfying the requirement due to factors such as a large volume, a limited Q value and limited power, while a dielectric filter has a relatively high Qf and power capacity, and can implement miniaturization, and therefore has an obvious advantage.
• A transverse magnetic (TM) mode dielectric filter has the foregoing advantage. However, in the TM filter, sufficient contact needs to be maintained between a dielectric resonator and upper and lower surfaces of a cavity in a long term to ensure good and stable performance, and therefore, how to secure the dielectric resonator becomes a key technology. A common TM mode dielectric filter includes a cavity, a dielectric resonator disposed in the cavity, and a main cover.
• In the prior art, an elastic component, such as a gasket or a thin cover, that produces an elastic acting force on the dielectric resonator is usually disposed between the dielectric resonator and the main cover, to achieve the purpose of securing the dielectric resonator. Because part of the elastic component is located within the cavity, in order to ensure electrical performance, the whole elastic component needs to be electroplated, causing a complex process and relatively high processing costs; besides, to produce an elastic force, the elastic component is bent to some degree in the cavity, causing a non-uniform current distribution and affecting the electrical performance. High-precision fitting is required between the elastic component and the cavity, between the elastic component and the main cover, and between the elastic component and a dielectric, increasing the processing and assembly difficulty.
SUMMARY
• The present invention provides a transverse magnetic (TM) mode dielectric filter, which has a low precision control requirement and low costs and can ensure high reliability of electrical performance, thereby improving intermodulation performance and ensuring long-term stability.
• A transverse magnetic (TM) mode dielectric filter is provided, including an enclosure, a dielectric resonator, a main cover, and an elastic component, where
• a columnar resonant cavity is formed in the enclosure, and the enclosure is disposed with an opening at an end located at the resonant cavity;
• the dielectric resonator is columnar, is disposed in the resonant cavity, and is disposed coaxially with the resonant cavity; and one end of the dielectric resonator abuts against a bottom surface of the resonant cavity, where
• the main cover is secured between the elastic component and an open end of the enclosure;
• the main cover has an inner surface and an outer surface that are opposite to each other; a central part of the inner surface of the main cover is adhered to the other end of the dielectric resonator, and a periphery of the main cover is adhered to the open end of the enclosure; and
• the elastic component includes multiple elastic flaps; the multiple elastic flaps are evenly distributed around an axial direction of the dielectric resonator; one end of each of the elastic flaps is fixedly connected to the main cover, and the other end of each of the elastic flaps extends towards a central axis of the dielectric resonator to form a free end; and the free ends of the elastic flaps elastically act on a central part of the outer surface of the main cover, to provide an elastic force towards the dielectric resonator.
• In a first possible implementation manner, the inner surface of the main cover is a plane, and an end surface of the other end of the dielectric resonator is flush with an end surface of the open end of the enclosure.
• With reference to either of the foregoing implementation manners, in a second possible implementation manner, a first boss is disposed at the central part of the outer surface of the main cover, and the first boss protrudes along the central axis of the dielectric resonator and forms a protruding surface; and the free ends of the elastic flaps elastically abut against the protruding surface, so that the elastic flaps are elastically deformed.
• With reference to the foregoing second possible implementation manner, in a third possible implementation manner, shapes of outer edges of a cross-section of the first boss and a cross-section of the dielectric resonator are the same, and an outer diameter of the first boss is equal to or slightly greater than an outer diameter of the dielectric resonator.
• With reference to any of the foregoing implementation manners, in a fourth possible implementation manner, an annular slot is disposed between a periphery and the central part of the outer surface of the main cover.
• With reference to any of the foregoing implementation manners, in a fifth possible implementation manner, the elastic component further includes a positioning ring, and the positioning ring is disposed around the central axis of the dielectric resonator and is fixedly connected to the periphery of the outer surface of the main cover; and the elastic flaps are secured to an inner side of the positioning ring, and one end of the elastic flap is fixedly connected to the main cover by using the positioning ring.
• With reference to the fifth possible implementation manner, in a sixth possible implementation manner, the positioning ring and the multiple elastic flaps are integrally formed.
• With reference to the sixth possible implementation manner, in a seventh possible implementation manner, by means of mechanical processing on a board disposed with a through-hole at a center, the elastic component is disposed with multiple strip slots at the through-hole, the strip slot has one end closed and the other end open, and the open end of the strip slot is in communication with the through-hole; and the elastic flap is formed between two adjacent strip slots, and the positioning ring is formed at the closed end of the strip slot.
• With reference to any of the foregoing implementation manners, in an eighth possible implementation manner, the TM mode dielectric filter further includes a tuning screw and a nut; the dielectric resonator is of a hollow columnar structure;
• a screw hole is disposed at a center of the main cover, the tuning screw is in threaded connection to the screw hole, one end of the tuning screw is located in the dielectric resonator, and a gap is disposed between the tuning screw and an inner wall of the dielectric resonator; and the nut is in threaded connection to the tuning screw and abuts against the main cover.
• With reference to the eighth possible implementation manner, in a ninth possible implementation manner, a second boss is further disposed at a central part of the main cover, and the second boss protrudes along the central axis of the dielectric resonator; the screw hole is disposed in the second boss, the nut abuts against the second boss, and the free ends of the multiple elastic flaps are located on a periphery of the second boss.
• With reference to the ninth possible implementation manner, in a tenth possible implementation manner, in a case in which the first boss is disposed at the central part of the outer surface of the main cover, the second boss is disposed on the first boss, connection between the second boss and the first boss is step-like, and the protruding surface is an annular step plane surrounding the second boss.
• In the TM mode dielectric filter provided in the present invention, the main cover fits with the enclosure and the dielectric resonator in an adhering manner; the elastic component is disposed on the outer surface of the main cover, and the elastic component does not need to be electroplated, which reduces processing costs; an acting force is transferred by using the main cover, high precision is not required between the elastic component and the dielectric resonator, and a requirement on tolerance is low, reducing processing costs; a pressure towards the dielectric resonator is produced by the multiple elastic flaps that are evenly distributed, and the pressure is transferred to the dielectric resonator by using the main cover, so that a pressure applied to an end surface of the dielectric resonator is uniformly and stably distributed in an axial direction, to ensure a uniform current density inside the resonant cavity and ensuring electrical performance. In this way, intermodulation performance can be greatly improved and kept stable in a long term, thereby preventing the dielectric resonator from breaking.
BRIEF DESCRIPTION OF DRAWINGS
• To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly describes the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the present invention, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.
• FIG. 1 is an exploded schematic diagram of a TM mode dielectric filter according to a possible implementation manner of the present invention;
• FIG. 2 is an axial sectional view of the TM mode dielectric filter inFIG. 1;
• FIG. 3 is a schematic diagram of a main cover of the TM mode dielectric filter inFIG. 1; and
• FIG. 4 is a schematic diagram of an elastic component of the TM mode dielectric filter inFIG. 1.
DESCRIPTION OF EMBODIMENTS
• The following describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
• As shown inFIG. 1 toFIG. 4, the present invention provides a transverse magnetic (TM) mode dielectric filter, and the TM mode dielectric filter may be a TMO1 main mode dielectric filter or certainly, may be a TM mode dielectric filter in another form. The TM mode dielectric filter includes an enclosure1, adielectric resonator2, amain cover3, and an elastic component4. Themain cover3 and the elastic component4 are secured to the enclosure1, and thedielectric resonator2 is secured in the enclosure1; and the elastic component4 may provide an elastic force to themain cover3, so that a uniform downward pressure is applied from themain cover3 to an upper end surface of thedielectric resonator2, thereby improving intermodulation performance of thedielectric resonator2.
• A columnarresonant cavity10 is formed in the enclosure1, and the enclosure1 is disposed with an opening at an end located at theresonant cavity10. The enclosure1 is made of a metal material or a plastic alloy material and includes some metal elements having an effect of shielding an electromagnetic wave. Thedielectric resonator2 is columnar, is disposed in theresonant cavity10, and is disposed coaxially with theresonant cavity10; one end of thedielectric resonator2 abuts against a bottom surface of theresonant cavity10. Thedielectric resonator2 is generally made of a ceramic dielectric and may be doped with rare metals such as rare earth. In this embodiment, thedielectric resonator2 is of a hollow columnar structure. It can be understood that in the field of TM mode dielectric filters, thatdielectric resonator2 is of a hollow columnar structure refers to that thedielectric resonator2 is columnar as a whole, and is disposed with a through-hole running through thedielectric resonator2 at a central axis position of thedielectric resonator2.
• In this embodiment, a positioning structure fitting with thedielectric resonator2 is disposed at a central position of a bottom surface of theresonant cavity10. In this embodiment, thedielectric resonator2 is of a hollow columnar structure, the positioning structure is aboss10, an outer diameter of thepositioning boss10 fits with an inner diameter of thedielectric resonator2, and an outer diameter of a positioning boss11 fits with an inner diameter dimension of thedielectric resonator2 and tolerance, to implement positioning between a bottom end of thedielectric resonator2 and the enclosure1 and ensure that thedielectric resonator2 does not become loose when mounted on the positioning boss11 on the bottom surface of theresonant cavity10; besides, in this case, thedielectric resonator2 is in a free state and can be replaced. Herein, in another implementation manner, the positioning structure may be a positioning blind via, where an aperture of the positioning blind via fits with the outer diameter of the dielectric resonator, and thedielectric resonator2 is of a hollow structure or is a solid column, with one end capable of being inserted into the positioning blind via to implement positioning.
• Themain cover3 includes an inner surface and an outer surface that are opposite to each other. Herein, it can be understood that the inner surface of themain cover3 is a surface located inside theresonant cavity10, and the outer surface is a surface, located outside theresonant cavity10, of themain cover3. A central part of the inner surface of themain cover3 is adhered to the other end of thedielectric resonator2, and a periphery of themain cover3 is adhered to an open end of the enclosure1. Preferably, the inner surface of themain cover3 is a plane, and an end surface of the other end of thedielectric resonator2 is flush with an end surface of the open end of the enclosure1. In this embodiment, a height of thedielectric resonator2 is the same as a depth of theresonant cavity10; after themain cover3 and the enclosure1 are assembled, the periphery of themain cover3 is adhered to the open end of the enclosure1, and a central part of themain cover3 can abut against and be adhered to thedielectric resonator2, to facilitate assembly and connection and lower processing difficulty. The inner surface of themain cover3 is a plane, which can ensure a uniform current distribution in the resonant cavity and ensure electrical performance of the filter. Herein, in another implementation manner, the inner surface of themain cover3 may not be a plane; a protrusion may be disposed at the central part of themain cover3, and the protrusion can abut against an end surface of thedielectric resonator2 and make the end surface of thedielectric resonator2 not flush with the end surface of the open end of the enclosure1.
• In this embodiment, because only the inner surface of themain cover3 is located in theresonant cavity10, only the inner surface of themain cover3 needs to be electroplated to ensure electrical performance in theresonant cavity10, and the outer surface may be electroplated or may not be electroplated, to reduce processing operations and processing costs. Themain cover3 is made of a metal material; for example, themain cover3 may be made of aluminum, copper, steel, or any material with conductive performance; themain cover3 may be implemented by means of machining or die casting.
• The elastic component4 is disposed on the outer surface of themain cover3, and the elastic component4 includes apositioning ring42 and multipleelastic flaps41. Thepositioning ring42 is disposed around a central axis of thedielectric resonator2 and is fixedly connected to a periphery of the outer surface of themain cover3. The elastic flaps41 are secured to an inner side of thepositioning ring42, one end of theelastic flap41 is fixedly connected to themain cover3 by using thepositioning ring42, and use of thepositioning ring42 can facilitate assembly and connection of the multipleelastic flaps41. The multipleelastic flaps41 are evenly distributed around an axial direction of thedielectric resonator2. The elastic flaps41 extend towards the central axis of thedielectric resonator2 to form free ends; the free ends of theelastic flaps41 elastically act on a central part of the outer surface of themain cover3, to provide an elastic force towards thedielectric resonator2. Theelastic flap41 is elastic, where the free end moves relatively, and an elastic force can be produced by means of elastic deformation of theelastic flap41.
• Because multipleelastic flaps41 are provided and are evenly distributed around thedielectric resonator2, a uniform pressure towards thedielectric resonator2 can be produced on the periphery of thedielectric resonator2, ensuring that a pressure applied to themain cover3 is uniformly distributed on the periphery; a uniform downward pressure is also applied from themain cover3 to an upper end surface of thedielectric resonator2, ensuring a uniform current density inside theresonant cavity10. Therefore, intermodulation performance of thedielectric resonator2 can be improved. The pressure is distributed uniformly and stably, therefore avoiding a problem that when the temperature cyclically changes, thedielectric resonator2 breaks due to interference or an excessive pressure of thedielectric resonator2 caused by a relatively large amount of accumulated tolerance.
• Preferably, theelastic flap41 and thepositioning ring42 are both tabular, and theelastic flap41 in a free state is flush with thepositioning ring42, to facilitate processing and preparation. Thepositioning ring42 and the multipleelastic flaps41 may be integrally formed; by means of mechanical processing, such as machining stamping, linear cutting, laser cutting or the like on a board disposed with a through-hole at a center, the elastic component4 is disposed withmultiple strip slots40 at the through-hole along a radial direction; thestrip slot40 has one end closed and the other end open, and the open end of thestrip slot40 is in communication with the through-hole; theelastic flap41 is formed between twoadjacent strip slots40, and thepositioning ring42 is formed at the closed end of thestrip slot40, to facilitate processing and preparation. A quantity and sizes of theelastic flaps41 can be determined according to actual product requirements, and pressures produced by theelastic flaps41 are also different depending on the quantity and the sizes of the elastic flaps41. The elastic component4 may be made of spring steel, so that the elastic component4 has an advantage of having stable and enduring elasticity, ensuring that performance of the filter is stable in a long term and the performance remains unchanged even under a harsh ambient temperature. Herein, in another implementation manner, the elastic component4 may also be made of a material capable of providing elasticity that is stable in a long term, for example, an elastic steel board or an elastic composite material.
• In this embodiment, afirst boss31 is disposed at the central part of the outer surface of themain cover3, and thefirst boss31 protrudes along the central axis of thedielectric resonator2 and forms a protrudingsurface31 a; on the central axis of thedielectric resonator2, the protrudingsurface31a of thefirst boss31 is away from the dielectric resonator with respect to the periphery of the outer surface of themain cover3, and the free ends of theelastic flaps41 elastically abut against the protrudingsurface31 a. Thefirst boss31 can enable the central part of themain cover3 to have a height difference with respect to the periphery of themain cover3; after the elastic component4, themain cover3, and the enclosure1 are assembled, the free ends of theelastic flaps41 are enabled to move towards a direction away from thedielectric resonator2, and theelastic flaps41 are elastically deformed to produce an elastic force, providing a pressure to thefirst boss31 and thedielectric resonator2.
• Shapes of outer edges of a cross-section of thefirst boss31 and a cross-section of thedielectric resonator2 are the same, and an outer diameter of thefirst boss31 is equal to or is slightly greater than an outer diameter of thedielectric resonator2, to ensure that the dielectric resonator is uniformly stressed. In this embodiment, the outer edge of the cross-section of thefirst boss31 is circular, that is, thefirst boss31 is cylindrical, and the outer edge of the cross-section of thedielectric resonator2 is also circular. Correspondingly, both outer peripheries of the cross-sections of thefirst boss31 and thedielectric resonator2 may also be square or in another shape.
• Asecond boss32 may further be disposed at the central part of themain cover3, and thesecond boss32 protrudes along the central axis of thedielectric resonator2; ascrew hole30 is disposed in thesecond boss32, anut6 abuts against thesecond boss32, and the free ends of the multipleelastic flaps41 are located on a periphery of the second boss. Thenut6 and theelastic flaps41 separately abut against different positions, and the use of thesecond boss32 can prevent thenut6 from touching theelastic flaps41 when thenut6 is rotated, avoiding affecting disassembly and assembly.
• In this embodiment, thesecond boss32 is disposed on thefirst boss31, connection between thesecond boss32 and thefirst boss31 is step-like, and the protrudingsurface31a is an annular step plane surrounding the second boss. A structure of themain cover3 is set properly and can prevent thenut6 from touching theelastic flaps41 while ensuring effective deformation of the elastic flaps41.
• Anannular slot33 is disposed between the periphery and the central part of the outer surface of themain cover3; a thickness of an area between the center and the periphery of themain cover3 may be reduced by using theannular slot33; theannular slot33 can ensure that when a force acts on thefirst boss31, a tensile force produced by deformation of thefirst boss31 being stressed can be desirably absorbed in time by theannular slot33; after theannular slot33 is added, an area of themain cover3 located at a lower position is thin enough, facilitating deformation of the central part of themain cover3 relative to the periphery, and a counter acting force against thefirst boss31 is relatively small, thereby ensuring that the force of theelastic flaps41 is fully applied to thedielectric resonator2.
• In this embodiment, the TM mode dielectric filter may further includemultiple fastening screws7, and themultiple fastening screws7 are evenly distributed along the open end of the enclosure1, so that the elastic component4 and themain cover3 are uniformly stressed, ensuring electrical performance. Thefastening screw7 sequentially runs through thepositioning ring42 and the periphery of themain cover3, to be connected to the open end of the enclosure1 in a threaded manner; the elastic component4 and themain cover3 are secured to the enclosure1 by using the fastening screws7, facilitating assembly, disassembly and maintenance. Thefastening screw7 is made of a steel material, to ensure that thefastening screw7 has particular mechanical strength and ensure reliability of connection between the elastic component4, themain cover3, and the enclosure1. Herein, in another implementation manner, fixed connection between the elastic component4, themain cover3, and the enclosure1 may also be implemented by means of welding, riveting, clamping, and the like.
• The TM mode dielectric filter may further include a tuning screw5 and thenut6. Thescrew hole30 is disposed at the center of themain cover3, the tuning screw5 is in threaded connection to thescrew hole30, and thenut6 is in threaded connection to the tuning screw5, to fasten the tuning screw5 to themain cover3. One end of the tuning screw5 is located in thedielectric resonator2, and a gap is disposed between the tuning screw5 and an inner wall of thedielectric resonator2; and filtering is implemented by means of tuning by the tuning screw5. Herein, in another implementation manner, thedielectric resonator2 may be a solid cylinder, and tuning is performed in another manner to implement filtering, without the need of setting the tuning screw5 and thenut6.
• In the present invention, by means of fitting between structures of the elastic component4 and themain cover3, interference press fit is implemented by using the elasticity of theelastic flaps31, thedielectric resonator2 does not need to have a relatively large magnitude of interference, a pressure towards thedielectric resonator2 is produced by using the multiple elastic flaps that are evenly distributed, so that a uniform and stable pressure is produced around thedielectric resonator2, to ensure a uniform current density inside theresonant cavity10 and ensure electrical performance. In this way, intermodulation performance can be greatly improved and kept stable in a long term, thereby avoiding a problem that a dielectric breaks under an ambient temperature due to improper pressure control. Themain cover3 fits with the enclosure1 and thedielectric resonator2 in an adhering manner, the elastic component4 is disposed on the outer surface of themain cover3, and the elastic component4 does not need to be electroplated, which reduces processing costs, does not require high precision between the parts, and has a low requirement on tolerance, thereby reducing processing costs and effectively resolving problems of a large variety of parts, complex assembly, and a high precision requirement in the prior art.
• Parts of the TM mode dielectric filter provided in the present invention are assembled and connected by means of threads rather than a welding solution; intermodulation performance can still be lifted by using the elastic component4; and the dielectric resonator can be conveniently disassembled to be replaced, to facilitate assembly and maintenance of the TM mode dielectric filter.
• In this embodiment, multiple TM mode dielectric filters may form a filter module, where multiple enclosures1 may be an integrated structure, that is, multiple resonant cavities may be provided in a large enclosure; multiple elastic components may be integrally formed or may be multiple parts that fit with multiple resonators respectively.
• The foregoing implementation manner is one specific implementation manner of the invention. In addition, in the foregoing implementation manner, some of technical features of the TM mode dielectric filter may be modified and replaced to achieve a same or similar technical effect; these modifications and replacements include, but are not limited to, one or more of the following implementation manners.
• In the foregoing implementation manner, theelastic flap41 and thepositioning ring42 are both tabular, to facilitate processing and preparation. It should be noted that theelastic flap41 and thepositioning ring42 are not limited to being tabular. In other implementation manners, theelastic flap41 may also be rod-shaped or columnar; and thepositioning ring42 may also be annular block-shaped, frame-shaped, or in another shape.
• In the foregoing implementation manner, the multipleelastic flaps41 are connected by using thepositioning ring42 to form an integrated structure, and theelastic flaps41 are fixedly connected to the main cover by using the positioning ring. In another implementation manner, the elastic component4 may include multipleelastic flaps41 only; theelastic flaps41 are mutually independent parts; theelastic flaps41 may be fixedly connected to the main cover one by one; theelastic flap41 is strip-shaped, where one end of theelastic flap41 is directly fixedly connected to themain cover41, for example, may be fastened by using a bolt; and the free end of theelastic flap41 abuts against the first boss. Further, to facilitate positioning of theelastic flaps41, multiple positioning structures may be disposed on the first boss; the positioning structures may be positioning holes, positioning bumps, positioning slots, and the like; the positioning structures are in one-to-one fitting with the free ends of the elastic flaps, to facilitate positioning of the free ends of the elastic flaps and ensure that the strip-shaped elastic flaps do not shift, so that the multiple elastic flaps are evenly arranged above the main cover around the first boss and are fastened by screws, making the arrangement more flexible.
• In the foregoing implementation manner, a deformation effect of theelastic flaps41 may be improved by using thefirst boss31. In another implementation manner, thefirst boss31 may not be disposed at the central part of themain cover3; in a free state, theelastic flaps41 are designed to be in a bent shape, and the free ends of theelastic flaps41 are bent towards thedielectric resonator2, so that the free ends of theelastic flaps41 can directly abut against the central part of the outer surface of themain cover3; after assembly, the free ends may move towards a direction away from the dielectric resonator so that theelastic flaps41 are elastically deformed, to provide a pressure to the dielectric resonator.
• In the foregoing implementation manner, the free ends of theelastic flaps41 abut against the first boss, that is, the free ends of theelastic flaps41 directly abut against the main cover, to apply an acting force to the central part of themain cover3. In another implementation manner, a separate part may be disposed at the central part of the outer surface of the main cover to form a stressed component protruding from the main cover; the free ends of theelastic flaps41 abut against the stressed component. For example, after the tuning screw, the nut, and the main cover are assembled, the elastic component is assembled, and the free ends of theelastic flaps41 are made to abut against the nut, so as to use the nut as the stressed component; the elastic flaps indirectly apply an acting force to the main cover.
• Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention but not for limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features thereof, without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (11)

What is claimed is:

1. A transverse magnetic (TM) mode dielectric filter, comprising an enclosure, a dielectric resonator, a main cover, and an elastic component, wherein

a columnar resonant cavity is formed in the enclosure, and the enclosure is disposed with an opening at an end located at the resonant cavity;

the dielectric resonator is columnar, is disposed in the resonant cavity, and is disposed coaxially with the resonant cavity; and one end of the dielectric resonator abuts against a bottom surface of the resonant cavity;

the main cover is secured between the elastic component and an open end of the enclosure;

the main cover has an inner surface and an outer surface that are opposite to each other; a central part of the inner surface of the main cover is adhered to the other end of the dielectric resonator, and a periphery of the main cover is adhered to the open end of the enclosure; and

the elastic component comprises multiple elastic flaps; the multiple elastic flaps are evenly distributed around an axial direction of the dielectric resonator; one end of each of the elastic flaps is fixedly connected to the main cover, and the other end of each of the elastic flaps extends towards a central axis of the dielectric resonator to form a free end; and the free ends of the elastic flaps elastically act on a central part of the outer surface of the main cover, to provide an elastic force towards the dielectric resonator.

2. The TM mode dielectric filter according toclaim 1, wherein the inner surface of the main cover is a plane, and an end surface of the other end of the dielectric resonator is flush with an end surface of the open end of the enclosure.

3. The TM mode dielectric filter according toclaim 1, wherein a first boss is disposed at the central part of the outer surface of the main cover, and the first boss protrudes along the central axis of the dielectric resonator and forms a protruding surface; and the free ends of the elastic flaps elastically abut against the protruding surface, so that the elastic flaps are elastically deformed.

4. The TM mode dielectric filter according toclaim 3, wherein shapes of outer edges of a cross-section of the first boss and a cross-section of the dielectric resonator are the same, and an outer diameter of the first boss is equal to or slightly greater than an outer diameter of the dielectric resonator.

5. The TM mode dielectric filter according toclaim 1, wherein an annular slot is disposed between a periphery and the central part of the outer surface of the main cover.

6. The TM mode dielectric filter according toclaim 1, wherein the elastic component further comprises a positioning ring, and the positioning ring is disposed around the central axis of the dielectric resonator and is fixedly connected to the periphery of the outer surface of the main cover; and the elastic flaps are secured to an inner side of the positioning ring, and one end of the elastic flap is fixedly connected to the main cover by using the positioning ring.

7. The TM mode dielectric filter according toclaim 6, wherein the positioning ring and the multiple elastic flaps are integrally formed.

8. The TM mode dielectric filter according toclaim 7, wherein by means of mechanical processing on a board disposed with a through-hole at a center, the elastic component is disposed with multiple strip slots at the through-hole, the strip slot has one end closed and the other end open, and the open end of the strip slot is in communication with the through-hole; and the elastic flap is formed between two adjacent strip slots, and the positioning ring is formed at the closed end of the strip slot.

9. The TM mode dielectric filter according toclaim 1, wherein the TM mode dielectric filter further comprises a tuning screw and a nut; the dielectric resonator is of a hollow columnar structure; and

a screw hole is disposed at a center of the main cover, the tuning screw is in threaded connection to the screw hole, one end of the tuning screw is located in the dielectric resonator, and a gap is disposed between the tuning screw and an inner wall of the dielectric resonator; and the nut is in threaded connection to the tuning screw and abuts against the main cover.

10. The TM mode dielectric filter according toclaim 9, wherein a second boss is further disposed at a central part of the main cover, and the second boss protrudes along the central axis of the dielectric resonator; the screw hole is disposed in the second boss, the nut abuts against the second boss, and the free ends of the multiple elastic flaps are located on a periphery of the second boss.

11. The TM mode dielectric filter according toclaim 10, wherein in a case in which the first boss is disposed at the central part of the outer surface of the main cover, the second boss is disposed on the first boss, connection between the second boss and the first boss is step-like, and the protruding surface of the first boss is an annular step plane surrounding the second boss.

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